1. Technical Field
The present disclosure relates to a resonant magnetic coupling type non-contact power transmission technique for transmitting power wirelessly by resonant magnetic coupling.
2. Description of the Related Art
United States Patent Application Laid-Open Publication No. 2008/0278264 (which will be referred to herein as Patent Document No. 1 for convenience sake; see FIGS. 12 and 14, in particular) discloses a new type of wireless energy transfer system for transferring energy from one of two resonators to the other, and vice versa, through the space between them. That wireless energy transfer system couples the two resonators with each other via the evanescent tail of the oscillation energy of the resonant frequency that is produced in the space surrounding those two resonators, thereby transferring the oscillation energy wirelessly (i.e., by a non-contact method).
Meanwhile, the conventional electromagnetic induction technology is still used today. Many of electronic devices to which these power transmission techniques are applied will receive power with a constant voltage, go through some power conversion, energy transfer and other blocks, and then require the voltage applied to another device to be a constant one. As for audiovisual devices such as a TV set, for example, such a device will receive input power from an outlet that supplies a substantially constant AC power but independent circuits in that device, which eventually dissipate that power supplied, will operate with a predetermined voltage kept applied thereto. Even if the luminance on the screen varies, such a variation can also be coped with by changing the amount of current supplied. Such an operation that receives power with a constant voltage from a power supply and then outputs power with the constant voltage to a load will be referred to herein as a “constant-voltage operation”.